Measuring devices for determining a fill level or limit level of a medium in a container are known in a multitude of different designs. Thus, for instance, there are fill level measuring devices available, which work contactlessly and are mounted at, on or in a lid of the container and above the maximum expected fill level of the medium in the container. Essentially from above, these contactless fill level measuring devices emit measuring signals internally in the container, directed toward the medium. The signals are reflected at the surface of the medium and led back to the measuring device. From the reflected signals, or their travel time, the distance between the surface of the medium and the measuring device can be determined, and, from there, the sought fill level of the medium is derived considering the geometry of the container.
Known limit level measuring devices are usually mounted at a predetermined location or height on a sidewall of the container, such that they protrude into the container and serve there as so-called limit level switches. When they are used, for example, for overfill protection and, accordingly, are mounted at the position of maximum allowable fill level in the container, they produce a switching signal, upon being covered by the medium. The switching signal turns off, or interrupts, further inflow of the medium into the container. When the limit switches are used, for example, for pump protection and, accordingly, are mounted in the container at the position of minimum fill level, which must not be subceeded, or fallen beneath, they produce a switching signal, when they are uncovered by the medium. The switching signal, in this case, prevents a further pumping, or outflow, of the medium out of the container.
A special problem occurs in the case of these measuring devices for determining a fill level or limit level when they are essentially mounted externally on the container and their sensors, or transducers, extend into the interior of the container. If the container shape is unfavorable, or the mounting position of the measuring device is unfavorable, it is currently not possible to position, or orient, the measuring device in a desired manner with reference to the measuring location or the required line of measurement. Apparatuses are known, with the help of which an above-described fill level measuring device can be oriented, but these apparatuses permit only a very limited adjustment of the inclination angle of the measuring device and/or they do not seal the interior of the container.